This invention relates to tube holders for blood collection tubes and more particularly to a tube holder for use with collection tubes of different sizes.
Tube holders generally include a cylindrical body or barrel open at one end for receiving an evacuated blood collection tube and an end wall at the opposite end for supporting a double-ended needle cannula. The needle has a distal end for insertion into a vessel of a patient and a proximal end within the barrel for penetrating the stopper of the collection tube. The tube is guided by the barrel toward the proximal end of the needle so that the needle properly enters the central portion of the stopper to effect fluid communication with the interior of the tube.
A tube holder of given size will, of course, accommodate and accurately guide a blood collection tube of complementary size. However, since blood collection tubes employed in taking blood samples for various kinds of blood tests vary significantly in size, it is often necessary to employ tube holders of different sizes. Also, it is often desirable to take a number of blood samples for different blood tests from the same patient while maintaining the same tube holder needle in the vein of the patient in order to avoid multiple punctures. Where such collection tubes vary in size, difficulties can occur if an attempt is made to use the same tube holder for all such tubes. For example, it is difficult to maintain the holder steady with the distal portion of the needle in the patient, while attempting to properly seat the stopper of a small tube onto the proximal portion of the needle where the tube holder is of a size capable of use with a relatively large tube.